Monolithically integrated 128-channel hybrid mode/polarization/wavelength (de)multiplexer on silicon-on-insulator

In this paper, we proposed a 128-channel hybrid mode/polarization/wavelength (de)multiplexer by monolithically integrating four 16-wavelength-channel (de)multiplexers based on bi-directional MRRs arrays and an 8-channel hybrid mode/polarization (de)multiplexer. The hybrid mode/polarization (de)multiplexer consists of a polarization beam splitter (PBS) and cascaded six asymmetric directional couplers (ADCs). The present 128-channel hybrid (de)multiplexer utilizes four modes, dual polarizations, and sixteen wavelengths to improve the data transmission capacity of optical communication systems. For the fabricated hybrid (de)multiplexer, the channel spacing is 1.4 nm, and we used thermal tuning electrodes with a tuning efficiency of 0.45 nm/mW to calibrate resonance wavelengths. The measurement results show the insertion loss is 3 similar to 8.5 dB, the inter-mode crosstalk is -7 similar to-23 dB, and the inter-wavelength crosstalk is-8 similar to-20 dB. The proposed (de)multiplexer is a promising approach to enhance the transmission capacity and has great potential in high-speed data transmission.